Spheree lets you watch animated images in full 3D

It's official: we're well on the way to a true 3D display. This one, called Spheree, is the work of a team of researchers working together from the University of São Paulo, Brazil, and the University of British Columbia, Canada, and it's mesmerising to behold.

Like its name suggests, it's in the shape of a translucent sphere; inside, the viewer can see animations and images that appear to float in the centre; as the viewer moves around, they can see other sides of the object as their perspective changes.

And it's all based on optical illusion. Packed inside the Spheree are multiple mini-projectors, which shine the images onto the interior surface of the sphere. Special software designed by the team blends the projector images together for a single, seamless image.

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Because it is projected onto the surface of the globe, the next problem is the viewer's position in relation to Spheree. If the user is on one side and walks to the other, the view would usually distort or be obscured. For this reason, the device integrates motion-tracking software for user-targeted views: as the user moves around the sphere, the projected image follows, automatically correcting for perspective, appearing to stay in one place while the viewer moves around.

To do this, it uses infrared cameras that track a headband worn by the user.

"One of the emerging technologies that makes Spheree unique is that we use multiple mini-projectors, calibrated and blended automatically to create a uniform pixel space on the surface of the sphere," the team wrote.

"The calibration algorithm we developed allows for as many projectors as needed for virtually any size of sphere, providing a linear scalability cost for higher-resolution spherical displays. Spheree does not have any seams or blind spots, therefore rendered scenes are not occluded and the display can support stereo 3D experiences."

Although small projectors are usually low-resolution, the team circumvented this using a scalable multi-projector system called FastFusion, which automatically calibrates aligned projectors to blend separate projections.

But it's not just for passive viewing: using a leap motion gesture controller, the Spheree is able to integrate motion control, allowing users to interact with the models and images therein with their hands. Much like a sculptor can push, pull, turn, and sculpt a piece of clay, 3D modellers can directly create 3D models with their hands using software such as Blender via a connected computer.

The team demonstrated two versions of the Spheree at SIGGRAPH 2014 in Vancouver, Canada, earlier this month: a smaller 18cm display and a larger 51cm display.